In a conventional structure of map data to be used for displaying a map in an information terminal device, information on a component of a map and attribute information representing an attribute of this component are held together. In such a map data structure, it is necessary to associate the data on the component of the map with corresponding attribute data by some means.
Conventionally, when associating information on a component of a map with corresponding attribute information, proposed is a method of generating a data list in which pieces of information on the components are arranged and a data list in which pieces of attribute information are arranged so that the pieces of information on the components and the pieces of corresponding attribute information are arranged in the same order in these data lists (for example, in Patent Document 1).